A difficult obstacle associated with the exploration and production of oil and gas is management of significant ocean currents. These currents can produce vortex-induced vibration (VIV) and/or large deflections of tubulars associated with drilling and production. VIV can cause substantial fatigue damage to the tubular or cause suspension of drilling due to increased deflections. Various types of VIV suppression devices, for example helical strakes and fairings, can be attached to the tubular in an effort to suppress the effects of VIV on the tubular. While helical strakes, if properly designed, can reduce the VIV fatigue damage rate of a tubular in an ocean current, they typically produce an increase in the drag on the tubular and hence an increase in deflection. Thus, helical strakes can be effective for solving the vibration problem at the expense of worsening the drag and deflection problem.
Another solution is to use fairings as the VIV suppression device. Typical fairings have a substantially triangular shape and work by streamlining the current flow past the tubular. A properly designed fairing can reduce both the VIV and the drag. Fairings can be made to be free to weathervane around the tubular in response to changes in the ocean current.
An issue with both helical strakes and fairings is their cost. In order to be effective, helical strakes must typically cover about 85-90 percent or more of each section of the tubular requiring suppression. Fairings typically require coverage of 70 percent or more of each section requiring suppression. This results in a large number of fairings and strakes for a typical application, which can be very expensive and the added weight makes running and retrieving tubulars from the sea floor difficult. Even more expensive is the cost associated with retrofitting suppression devices underwater, which requires expensive installation costs for each unit installed.